Vouchers are free, just have to get in line and wait. Vouchers are only for Saturday and Sunday, and Holidays that fall on a weekday. If you go w/the group, some of the guys that have been there have figured out the easiest way to get vouchers, follow them.
Need an ORV for any vehicle you will drive in the dunes, not sure what they cost for out of state, but you can buy them at dune entrance. If you are just towing your quad into the parking lot and leaving your truck in the lot, it will not need one.
All vehicles that enter park period must have state park pass. Will need one for truck and every quad, bike, etc.
And no bikes have to be titled or anything like that to get passes.
If you don't already have one, whip flags are fairly priced priced at various locations in town. If I have missed anything, feel free to ask. I live 2 hrs away and am there almost every other weekend between Memorial day and Labor day, so the ones who are farther out should pic a few possible weekends and post as it will be easier for us residents to plan and attend.